>Except that even now I’m too immature and stupid to know what they are.

This is the bigger problem, not the type of car or clothes you drive. I dress like a schlub and drive a Toyota and don't feel any of the social pressures you're talking about. I think it's in your head.

>145 -> 120 IQ decline

You're also putting way way too much emphasis on this test. The methodology of IQ tests is also entirely questionable. I'd hardly be judging myself as a parent based on this.